clear;
data1 = load('c1.txt');
x1 =data1(:,1);
y1 = data1(:,2);
data2 = load('c2.txt');
x2 =data2(:,1);
y2 = data2(:,2);
data3 = load('c3.txt');
x3 =data3(:,1);
y3 = data3(:,2);
data4 = load('c4.txt');
x4 =data4(:,1);
y4 = data4(:,2);
plot(x1,y1,'r')
hold on
plot(x2,y2,'g')
plot(x3,y3,'b')
plot(x4,y4,'c')
x = -1:0.02:1;
for i = 1:101
    y(i) = 1/(1+25*x(i)*x(i));
end
plot(x,y,'k')
legend('n=5','n=10','n=15','n=20','f')